2013 Colorado State University

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Vehicle Description Form
(Form 6)

Human Powered Vehicle Challenge 2013

Latin America: Univ Simon Bolivar, Caracas, Venezuela Feb 22-24
West: NASA Ames Research Ctr, Moffett Field, CA April 12-14
East: Ferris State University, Big Rapids, MI April 26-28

http://go.asme.org/HPVC

This required document for all teams is to be incorporated in to your Design Report. Please Observe Your
Due Dates
EAST March 25
Latin America Feb 1
WEST March 11

Vehicle Description
Competition Location:
School name:
Vehicle name:

NASA Ames Research Center, Moffett Field, CA
Colorado State University
RamRide

Vehicle number

23

Vehicle type

Unrestricted X

Speed_______

Vehicle configuration
Upright
Prone
Frame material
Fairing material(s)
Number of wheels

Semi-recumbent X
Other (specify) ________
4130 Chromoly Steel
Ripstop Nylon, Aluminum, Chromoly Steel
3

Vehicle Dimensions (please use inches, pounds)
Length
95in
Width
32in
Height
46.5in Wheelbase 47.5in
Weight Distribution Front 31.75lbs
Rear 21.16in
Wheel Size
Front 16in Rear
Frontal area
1426in2
Steering
Front
X
Rear
Braking
Front
X
Rear
Estimated Cd
0.625

Total 53.79lbs

29in

Both

Vehicle history (e.g., has it competed before? where? when?) Our vehicle has been built from
scratch. Some of the design inspiration came from past CSU HPVC projects and some has come
from other forms of human powered transportation. The vehicle has never competed before in
any competition in any part of the world.

Competition Report
Colorado State University, RamRide
Vehicle Number: 23
Team Members: Steve Caskey, Blake Miner, Francsico Martinez, JC Coughlin, Jake Scheopflin,
John Wolf
Contact Information:
- John Wolf: 410-596-9920, [email protected]
- Blake Miner: 319-431-3829, [email protected]
- Steven Schaeffer (faculty advisor): [email protected]

[03/11/2013]

Vehicle 3-D Drawing
Wheel Base: 47.5 in
Track Width: 28 in
Overall Length: 95 in
Overall Width: 32 in
Weight: 53.79 lbs
Height: 46.5 in

Figure 1: Isometric View

Figure 2: Top View

Figure 3: Front View

Figure 4: Left Side View

Abstract
In recent years the rise in demand for fossil fuels has also increased the demand for clean
renewable power sources for people everywhere especially in lesser developed countries where
gasoline vehicles are sparse. Human powered vehicles (HPVs), such as bicycles, are one of the
purest forms of sustainable energy. Bikes are common throughout the world and have gone
through many improvements over the centuries to make them lighter, faster, more economically
and environmentally friendly. The 2013 Colorado State University design team took all these
factors into consideration when it went about a complete redesign and production of its
recombinant tadpole tricycle. The redesign was focused on making a stable, easy-to-ride, safe,
form of transportation whether it’s for a quick ride down to the supermarket or a longer trip to
see a friend in the next town over. Trips like these will usually call for storage space which we
included in the form of two removable plastic panniers perfect for carrying groceries or hauling
water. The tricycle was constructed from chromium steel, mindful that many people here and in
other countries have the tools to repair steel more readily available compared to other materials.
A lightweight fabric fairing was integrated into the design to reduced drag while protecting the
rider from the environment, and again easily repaired if damaged. The rigid steel frame was
designed to include a roll protection system to protect the rider in the event of a rollover but can
also be removed to make the vehicle smaller for storage or transport. An adjustable boom was
included in the design to accommodate a five inch difference in the length of a rider’s legs. The
CSU RamRide recombinant tricycle was designed with utility, convenience, and economics in
mind.

i

Table of Contents
Design ........................................................................................................................................ 1
Objective ................................................................................................................................. 1
Background ............................................................................................................................. 1
Prior Work............................................................................................................................... 2
Design Specifications .............................................................................................................. 2
Concept Development.............................................................................................................. 2
Innovation ............................................................................................................................... 4
Analysis...................................................................................................................................... 4
RPS Analysis ........................................................................................................................... 4
Structural Analysis .................................................................................................................. 6
Aerodynamic Analysis ........................................................................................................... 10
Cost Analysis......................................................................................................................... 12
Other Analysis ....................................................................................................................... 17
Testing ..................................................................................................................................... 21
RPS Testing ........................................................................................................................... 21
Developmental Testing .......................................................................................................... 22
Performance Testing .............................................................................................................. 23
Safety ....................................................................................................................................... 24
Aesthetics ................................................................................................................................. 26
Conclusion ............................................................................................................................... 26
Comparison ........................................................................................................................... 26
Evaluation ............................................................................................................................. 26
Recommendations ................................................................................................................. 27
Conclusion ............................................................................................................................ 27
References................................................................................................................................ 28
Appendix I (Innovation Report) ............................................................................................. 29
Objective ............................................................................................................................... 29
Need ...................................................................................................................................... 29
Description ............................................................................................................................ 29
Literature Review .................................................................................................................. 30
Testing and Evaluation .......................................................................................................... 30
Market Analysis .................................................................................................................... 31
Conclusions and Recommendations ....................................................................................... 31
References ............................................................................................................................. 31

ii

Design
For the 2013 AMSE HPVC Competition, the CSU team will design and fabricate a
partially faired, rear wheel drive, supine recumbent tricycle. The team has been working on
adequately validating the frame, roll protection system, storage, steering, drivetrain, and fairing
designs. The frame will is made of 4130 Chromoly steel. The rider will steer the vehicle via
direct steering, will brake via mechanical disc brakes on each front wheel, and propel the vehicle
up to a desired speed of 30mph via an 8 speed internally shifting rear hub. In order to reduce
drag and protect the rider from the elements the fairing will be made of Ripstop fabric and
supported by tent poles. This fairing will also double as a tent allowing the user to sleep under a
light covering. The vehicle will also be equipped with reusable, removable, lightweight, and
waterproof cat-litter-bin panniers (one on each side). As an added feature, the vehicle will be
equipped with running lights powered by a side-wall wheel generator and will also collapse with
a few bolts.
Objectives
 Produce a human powered vehicle within compliance with the 2013 ASME HPVC rules.
 Place within the top 3 overall of all competing teams.
 Win endurance event.
 No mechanical failures at competition.
 Produce a vehicle weight of 65lbs or less.
 Produce a vehicle that costs no more than $3,000.
Mission Statement
To create a sustainable, reliable, multi-functional, and competitive human powered
vehicle to compete in the 2013 American Society of Mechanical Engineers Human Powered
Vehicle Competition.

Background
As the American Society of Mechanical Engineers (ASME) Human Powered Vehicle
Challenge (HPVC) has progressed over the years the practicality aspect of the challenge has
become a more important focus. The judges are looking for realistic functions, such as being
able to stop and pick up groceries, rather than just how fast a HPV can go. The HPVs will be
judged on design, safety, innovation, and performance. With the world struggling to break free
of fossil fuels, HPVs are starting to gain more and more attention. Corporations and universities
from all around the world are funding programs and hosting HPVC events to show the new
concepts and innovations in the field [8].
Colorado State University (CSU) has placed in the top four at every HPVC since 2002 in
one of the events at the competition, excluding 2012 when they did not compete [9]. The event
most commonly placed high in was the utility competition in which they have numerous first and
second place wins. Their last first place finish was in the utility event in 2009 [9]. From articles
and pictures found online most of the vehicles developed by CSU have been a tadpole
configuration (2 wheels in the front and one in the back), supine recumbent with some type of an
aerodynamic faring. In recent CSU has strived to match the spirit of practicality with spaces on
the vehicle where goods can be stored and carried. Figure 5 shows the 2009 CSU HPV [10].

1

Prior Work
Aside from researching prior CSU vehicles, the all of the work for the new vehicle was done
within the current academic year and was done so from scratch. Our team has no existing
vehicles to work off of or build from that competed in past competitions.
Design Specifications
Design Specification
Vehicle Weight < 65lbs
Top Speed > 30mph
Turning Radius < 20ft
Ground Clearance >3in
Entry/Exit Vehicle <7.5s
Braking <19.7ft from 15.5mph
RPS Top Load ≥ 600lbs
RPS Top Elastic Deflection ≤ 2in
RPS Side Load ≥ 330lbs
RPS Side Elastic Deflection ≤ 1.5in

Table 1: Design Specifications
Justification
More efficient riding, easier to handle
Necessary to be competitive
Required by competition rules
Required by competition course
Necessary to be competitive
Required by competition rules
Required by competition rules
Required by competition rules
Required by competition rules
Required by competition rules

Method Used To Develop
Minimize weight in design
Gear ratio calculation
Steering calculation
Inherent in design
Optimized in fairing design
Mechanical disc brakes
3-D modeling and FEA
FEA
FEA
FEA

Concept Development and Selection Methods
The frame configuration, as well as the RPS, steering, fairing, energy storage, and storage
subsystems, were selected using a Pugh matrix concept selection method. The outcome of the
Frame Configuration Pugh matrix can be seen below in Figure 6. As a group we sat down and
evaluated each of the criteria for each of the categories. The highest number of positives was
chosen as the configuration or subsystem concept that was designed around. One subsystem, the
drivetrain, was evaluated using a weighted decision matrix instead of a Pugh decision matrix due
to the fact that there was no easy base with which to compare. The five packages were weighted
with numbers 1-5 on their ability to perform or satisfy the criteria as seen in Figure 7. Similar to
the Pugh Decision Matrix though, as a group we sat down and evaluated each of the criteria for
each of the categories. The highest total score was chosen as the configuration concept that was
designed around. Figure 5 shows our organizational timeline for the entire project.

Figure 5: Organizational Timeline
2

Figure 6: Pugh Matrix of Frame Configuration Subsystem

#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

Schlumpf Drive
Coninuously
Front chainring and Schlumpf Drive
and internal
shifting hub
Front chainring and
Criteria
Weight regular cassette
and internal
shifting rear hub with regular internal shifting rear hub
rear hub
shifting rear hub
with Belt
front chainring
Routing
4
2
3
1
3
3
4
Part availability
5
2
1
2
3
4
Ease of installation
4
2
2
5
5
5
Troubleshooting
5
2
2
2
3
5
Compatability with recumbents
3
3
2
3
4
4
Weight
3
3
4
4
4
5
Cost
4
1
1
3
3
3
Access to moving parts
5
2
2
2
3
3
Range of gear ratios
5
5
5
3
4
5
Serviceability
5
2
2
2
3
3
Complexity
3
2
2
2
3
4
Durability
2
5
5
4
4
4
Lifespan
2
3
5
4
4
5
Required maintenance
2
3
5
4
4
5
Potential for failure
2
4
4
4
4
Total Score
216
174
179
199
227

Figure 7: Weighted Decision Matrix of Drivetrain Subsystem

3

Innovation
As called for by the competition to address third world problems and as an innovation
effort the fairing will be equipped with extra material folded from the drivers chin underneath of
the fairing. The rider can remove the fairing from the vehicle, unfold the extra material, and use
guy-lines to tie down the fairing to the ground and take cover from the elements and the night.
This was thought to be desirable for those who have to make long journeys but want to minimize
the amount of equipment that needs to be packed. If the rider does not have to pack a tent then
they can carry more of their goods and make more out of their journey.
Cat litter bins were reused in an innovative way by making them into panniers. This
offers a practical use for an item that would have otherwise been discarded. Compared to a
typical pannier, the cat litter bins are much more durable and they can hold water. They are also
easily transferred from one vehicle to another as long as the vehicle has a typical bicycle rack.
A lighting system that will provide light for the rider to see oncoming obstacles as well as
rear tail lights to add visibility of the rider will be included in this vehicle. All of the power
required for the lighting system will be generated by the rider. The generator must be pressed
against the wheel when the wheel is moving to generate power. This is beneficial because the
rider does not always have to deal with the resistance from the generator and it assures that our
vehicle will have no stored energy before a race or a ride begins.

Analysis
RPS Analysis
The complex geometry of the Rollover Protection System (RPS) combined with the
frame made computer finite element analysis (FEA) the only feasible and reliable means of
determining the stresses in the structures. Before beam analysis on the frame combined with the
RPS could be completed, preliminary FEA was done on the RPS to confirm accuracy for the
sake of safety. The RPS can be removed and the following analysis was completed with three pin
joints based on where the RPS slips over the main spine of the frame and where the two bolts
secure it. These restraints simulate its connection to the frame and essentially lock movement
and rotation. The ASME HPVC rules require the RPS to support at minimum of 600lbf 12
degrees from vertical as well as a 300lbf on the side with less than two inches of elastic
deflection. Our design team agreed upon a 1.5 safety factor for the entire vehicle but a safety
factor of 2 was integrated into the analysis by doubling the required 600lbf and 300lbf to 1200lbf
and 600lbf, respectively. The results of the FEA shown below in figures 8 and 9 display a
maximum stress well below the yield stress of chromoly (63ksi) as well deflection that is
fractions of an inch. Some results appeared abnormally high and approaching yield but after
inspection a few analyses had stress concentrations at joints where the welding would lower the
stress concentrations.

4

Figure 8: RPS FEA analysis of side load

Figure 9: RPS FEA analysis of top load
These FEA analyses allowed us to refine the shape and size of material. Most important
alterations that occurred from theses analysis is that wall thickness was reduced from .098 inches
down to .058 inches to save on weight while still achieving our desired strength. With the
knowledge that RPS could handle the required forces an analysis was then done on the frame to
make sure that it could also handle those forces.
Our Roll Protection System was designed to removable but is normally secured to the
frame using two M6 class 5.8 bolts. Hand calculation using shear equations were performed to
find that these bolts were well equipped for handling the required loads with a high safety factor
of 13.

5

Structural Analysis
In analyzing the frame finite element analysis (FEA) in Creo Parametric was utilized
along with hand calculations for forces that are incurred during braking and turning. Hand
calculations were also used to find the degrees of torsional deflection on the boom while
pedaling and also on the frame while pedaling. Below in Tables 2 and 3, the outcome of our
analysis of the frame is summarized.
Table 2: Finite Element Analysis (FEA)
Finite Element Analysis (FEA) In Pro/E Mechanica:
Yield Stress of 4130 Chromoly Steel
Design Stress with 1.5 Saftey Factor of 4130
600 lb Top Load
300 lb Side Load
250 lb Rider Load
500 lb Impact Load off of a 3" Curb on Frame
Yield Stress of Mild Steel
Design Stress with 1.5 Saftey Factor of Mild Steel
600 lb Top Load on Drop Outs

Stress (psi)
63,300
42,200
25,040
10,190
18,100
30,170
53,700
35,800
371

Displacement (in)
n/a
n/a
0.17
0.01
0.16
0.26
n/a
n/a
n/a

Table 3: Hand Calculations
Hand Calculations:
Braking Force at 20 mph in 15.5 ft
Force in Turn at 15 mph in a 20 ft radius
Degrees of Torsional Deflection on Boom from Pedaling
Degrees of Torsional Deflection on Frame from Pedaling
Force to Yield Tie Rod
Critical Load of Tie Rod for Buckling
Shear Force Required to Yield Steel Tie Rod Bolt
Force of Average Male Pushing a Vertical Cylinder
Force of Average Male Pulling a Vertical Cylinder

Results
272 lbf
240 lbf
1.68 deg
2.52 deg
1,457 lbf
322 lbf
1972 lbf
148 lbf
185 lbf

A size of 1.25” diameter with a wall thickness of 0.083” wall thickness was chosen for
the main frame and 0.875” diameter by 0.058” wall thickness was used for the seat and rear
triangle. The FEA was done using a beam model due to that most members on the bike had a
length that was much greater than the cross section dimensions. There were also difficulties in
having Creo complete the analysis when using shell and solid models. The objective in
performing the FEA was that we wanted to see the stresses that would be experienced from loads
such as the required loads of 600lb and 300lb along with other loads we believed the frame
would experience during operation. Being that 4130 chromoly steel is a ductile material all
stresses were reported as von Mises stresses. The rear dropouts were fully constrained in the x
and y directions while only the translation was constrained in the z axis. The front head tubes
were constrained fully except for letting it move transnationally in the x direction. The yield
stress of 4130 Chromoly steel is 63.3ksi [11]. With a safety factor of 1.5 our max design stress
was 42.2ksi. When the frame was loaded with a 600lb top load, the max stress was found to be

6

25ksi and the max defection was 0.17”. Both of these values meet our standards along with
competition standards. In loading the frame with the 300lb side load the max stress and
deflection were 10.2ksi and 0.01”, respectively which met all standards. The results of these tests
can be seen in Figures 9 and 10. Several other analyses where done including a rider weight of
250lb dispersed on the seat and a 500lb impulse load which would be incurred from a 250lb rider
rolling off of a 3” curb. The results of these tests are shown in Figures 10 and 11 below.

Figure 10: Max von Mises stress and deflection from a 600lb top load 12 degrees from vertical

Figure 11: Max von Mises stress and deflection from a 300lb side load

7

Figure 12: Max von Mises stress and deflection from a 250lb rider

Figure 13: Max von Mises stress and deflection from a 500lb impact load
Our dropouts were constructed with 1080 mild steel. FEA was again utilized to see the
effects of a 600lb top load. The dropout was constrained in all directions and rotations at the
radius of the axle slot. The max von Mises stress and deflection were 371lb and 1.3E-5”
respectively. The results can be seen in Figure 14 below.

8

Figure 14: Max von Mises stress and deflection from a 600lb top load on dropouts
Hand calculations were also done to find forces that would be experienced during braking
and turning. Equation (1) was used to find the acceleration associated with braking where V f
equals final velocity Vi equals initial velocity, α equals acceleration and x equals stopping
distance. Equation (2) was used to find the force experience in stopping where F equals braking
force m equals mass of the vehicle and rider and α equals acceleration [11].
(1)

(2)

Equation (3) was used to find the normal acceleration experienced while turning where αn equals
normal acceleration, V equals velocity and r equals turning radius [11]. For this analysis it was
assumed that tangential acceleration was much less than normal acceleration. Then Equation (2)
was again used to find force.
(3)

From a speed of 20mph stopping in 15.5ft the force incurred would be 272lbf. A 240lbf would
be experienced in a 20ft radius turn traveling 15mph. Because these forces were much lower
than the 600lb and 300lb forces no FEA was used for these types of forces.
Calculations for degrees of torsional deflection showed that there would be 1.68deg of
rotation in the boom and 2.52deg of rotation in the frame while pedaling. Equation (4) below
was used to find the degrees of rotation where theta equals radians of deflection, T equals torque,
L equals length, J equals second moment of area and G equals shear modulus [11].
(4)

9

Aerodynamic Analysis
Table 4: Objectives, methods, and results analysis summary
Objective
Method
Result
Discover theoretical drag
Equations and hand
CD is sufficient for fairing
coefficient
calculations
requirements
Confirm shear strength of tent Equations and hand
τ experienced by the pole <<
poles
calculations
τ7075-T6
Our vehicle is primarily a utility vehicle. It is designed to be highly functional and
versatile. Such is our fairing: it is designed to double as an aerodynamic device and a light
shelter. Because of the vehicles intent, conducting an in-depth analysis using modeling software
was deemed unnecessary for the scope of this project. From a basic hand calculation (Figure 16)
based on the environmental characteristics of Moffett Federal Airport on the day of 4/12/2013,
the typical power produced per kilogram of an amateur bicycle racer according to Wikipedia, the
frontal area of the fairing, and an assumed speed of 35 mph, the drag coefficient (CD) was
calculated to be approximately 0.153 as seen below. This calculation is specifically for the
fairing alone and does not include the entire vehicle assembly with the fairing. We can expect
that the drag coefficient of the entire vehicle to be greater than this. According Bicycle Science
[4], a typical bicycle and rider has a drag coefficient of approximately 0.7. Being that our
recumbent tricycle sits much lower to the ground and has a more aerodynamic configuration we
know what the vehicles drag coefficient will be less than 0.7 (that of bicyclist and rider). Given
the low CD of the fairing, we guess that our vehicles drag coefficient will be around 0.6-0.625.
None-the-less, the aerodynamic device will improve our ability to break through the wind, power
our vehicle efficiently, and ride for longer periods of time.

Figure 15: Fairing Side View(L) and Front View(R)
The frame construction calls for the main tent pole to fit inside a chromoly tube at each end of
the pole. This assembly causes the tent pole to be in complete shear with respect to the wind
force, assuming that the wind is coming head on. An analysis needed to be done to verify that the
force of the wind on the tent pole did not overcome its shear strength as seen below. For the
frame skeleton we are using DAC Featherlite NSL poles. These poles are aluminum but the exact
composition is a trade secret. For this reason we based the hand calculation using a competitor’s
top of the line lightweight aluminum poles made from 7075-T6 aluminum. The material data for
the 7075-T6 aluminum was found at (MatWeb). Since the shear stress experienced due to the
wind is much less than the material shear strength the tent pole will be able to withstand the
forces and is suitable for use in the prescribed assembly.

10

Figure 16: Hand calculation to estimate CD

Figure 17: Hand calculation to verify tent pole shear strength
11

Cost Analysis
In the following tables, you will see the production cost analysis for our competition
vehicle RamRide. This calculation is based on several key assumptions as seen in Table 5.
Table 5: Vehicle Production Cost Analysis Assumptions
1) Staff includes 2 welders, 3 seamstress, and 2 assemblers
2) 10 vehicles/month for three years
3) Outsourcing prices based on Mark's Precision Machining in Fort Collins,
CO
4) Estimate based off of vehicle as presented in competition
5) Rent 3000 sq-ft space for 3 years in Fort Collins, CO @ $5/SF/Year or
$45,000/3 years
6) All parts and materials listed are for one vehicle
7) Omit costs such as utilities, building maintenance, and taxes in calculations
8) Calculations are purely for manufacture and assemble, no design involved
9) Workers work 40 hours per week w/ two weeks un-paid leave
In order to get a good grip on the total amount of money spent on physically building the vehicle,
a table of all of the parts and materials was made via each subsystem and totaled (Table 6).
Table 6: Component/raw material/hardware expenses
Components/raw materials/hardware Expense
Quantity

Unit
Expense

Cat Liter Bins
Ortlieb Mounting System

1
1

$ 13.00
$ 25.00

1/2" ODX13" Clear Flexible Vinyl Plastic Tubing
Krylon Hunter Green Plastic Spray Paint
M4 SS Flat Washer

1
1
4

$
$
$

0.60
5.99
0.08

M4 x 10 mm SS Button Head Socket Cap Screw
M4 x 20 mm SS Button Head Socket Cap Screw

4
4

$
$

0.53
0.75

M4 x 25 mm SS Button Head Socket Cap Screw
M5 x 10 mm SS Button Head Socket Cap Screw
M5 x 15 mm SS Button Head Socket Cap Screw
Yellow 2" X 24" Reflective Tape
Nylon Black Upholstery Thread
M4 SS Acorn Nut
M5 Weld Nut
1/8" X 1.5" X 12" 6061-T6511 Aluminum Bar
3/4"X12" UHMW Virgin Plastic Natural Round
3/8"X12" 4130 Steel Round

4
2
5
1
1
1
2
1
1
1

$
$
$
$
$
$
$
$
$
$

0.80
0.50
0.73
4.99
2.49
0.16
0.24
0.99
3.22
1.33

3/8" OD 1/16"X60" Wall 4130 Steel Tube

2

$ 25.56

Parts and Materials
Storage

12

1"X12" Black Tubular Webbing
Total

8
45

$ 0.36
$ 125.54

Fairing

Brass Gromets 9/32"I.D., 1/8"thick
DAC Featherlight Aluminum Tent Poles
Isacord Thread, 1000m

Total

6
1
1
1
2
4
4
4
4
1
1
1
2
2
1
1
1
41

$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$

0.34
29.60
5.99
0.84
0.18
1.49
0.53
0.33
0.20
0.52
7.74
0.69
16.59
6.00
0.75
1.13
41.64
16.50
293.06

Total

1
1
1
1
1
1
1
1
2
1
2
1
2
1
1
1
19

$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$

51.71
303.00
119.34
19.43
12.35
5.40
12.30
11.74
1.68
304.24
21.20
25.20
3.20
3.20
42.52
35.93
998.52

1
1

$ 270.00
$ 60.00

4

Zinc-Plated Steel Clevis Pin 5/16X1.25
Hair Pin Clip 0.54X7/8
Eyebolt 3/8X6
Zinc Plated Steel Wing Nut w/ Nylon Insert 5/16-18
Hex Cap Screw 5/16X1
Stop Nuts 3/8-16
Socket Head Cap Screw 1/4-20X1
1000D Cordura
Webbing/ Strap Webbing 1inX1yard
X-pak fabric 1yardX54in
Carribeaner
Side release buckles, 1in
Allen Head Set Screw M10X16mm
Alloy Steel 4130 NORMALIZED Tube 0.5" x 0.065" x 0.37" Cut to: 48"
Clear Vinyl, 2 yards

Drivetrain
Alex Adventurer 36 hole rim and 36 282mm spokes
Shimano Alfine 8spd Internal Shifting Rear Hub
SRAM Apex 175mm 110bcd 46-36 Crankset
73mm Lugless Super Light Bottom Bracket Shell
Nexus 8spd Revo Grip Shifter
.25in Thick Aluminum Extruded
.5in Thick Aluminum Extruded
6mm Ball Bearing
12in-lb Steel Torsion Spring LH
Chain idler sprockets and chain
16inch Front Tire
700c Rear Tire
Front Tube
Rear Tube
Shimano M520 SPD Pedals
Avid BB-5 Mountain Mechanical Disc Brakes, pair
Steering
Front Wheels 16", pair
1" Headset, pair

13

Steering Spindles, pair
20mm Axel, pair
Handle Bar Assembly, pair
Tie Rod Kit

1
1
1
1
6

$
$
$
$
$

1
1
1
1
1
1
1

$ 157.78
$ 73.05
$ 15.18

20
27

$
0.34
$ 297.72

Sidewall Generator

1

$ 150.96

Shifter Cable Housing
Shifter Cable
M5 Adjusting Barrel

1
1
1

$ 24.00
$ 7.20
$ 1.76

5/8" 4130 Steel Round
3/16" X 3/4" 6061-T6511 Aluminum Bar
1/8" X 2.5" 6061-T6511 Aluminum Bar
SS Torx Thread-Forming Screw for Plastic, 2-28 X 3/4"
M6 x 25 mm SS Button Head Socket Cap Screw
M5 SS Flat Washer

1
1
1
1
1
1

$ 3.69
$ 0.82
$ 1.65
$ 10.31
$ 1.04
$ 0.10

M5 SS Nyloc Nut
Total

1
11

$ 0.45
$ 201.98

Total

8
8

$
5.64
$ 45.12

Total

270.00
30.00
59.40
8.49
697.89

Frame, Seat, RPS
Assorted Metal Order
1.25"OD 0.058" wall 4130 steel tube
1.375"OD 0.058" wall 4130 steel tube
M5X 1.75" bolt
Universal Spec-D Racing Seat Belt 4 Point Harness
Seat Material Foam Snadwich
Seat Cord
Brass Gromets 9/32"I.D., 1/8"thick
Total

$ 1.50
$ 28.22
$ 13.99
$ 1.20

Energy Storage

Accessories
Krylon Glowz Glow in the dark spray paint

Table 7: Prototype Cost Summary
Total Expenses
Income Sources
Project fund
Donations
Travel grant
Difference

Prototype Cost Summary
$
2,659.83
$
5,517.52
$
3,500.00
$
1,017.52
$
1,000.00
$
2,857.69
*Does not include student labor
**Travel grant cannot be applied to vehicle

14

Separate from the production cost summary, using the sum of all of the vehicle expenses
we were able to create a prototype cost summary for the project itself as seen in Table 7.
We also took into account the fact that we cannot physically manufacture every part in
house during full blown production so we accounted for some outsourcing costs. These costs are
based off of actual quotes from Mark’s Precision Machining in Fort Collins, CO. Table 8
outlines these costs.
Table 8: Outsourcing Expenses
Outsourcing Expense
Part

Expense

Boom Clamp
C.M. Sprung Lever Arm
C.M. stationary lever arm
Storage bin plates
Boom tube spacers

$
$
$
$
$

-

Thinking back on the all of the different manufacturing processes performed, we thought
of all of the primary tools and light duty equipment necessary to produce the vehicle in a
manufacturing space. This calculation is two parts and consists of the capital expenses
(investments) and the in-house labor expenses. As mentioned earlier in the assumptions (Table
5), the primary staff responsible for producing the vehicles includes two welders, 3 seamstresses,
and two assemblers. These workers work 40 hour weeks and have 2 weeks of unpaid time off.
Average salaries were found on www.indeed.com [7]. The following two tables explain the
capital and in-house labor expenses.
Table 9: Capital Expenses
Capital Expense
Capital Investments (including tooling)
Industrial Property 1-year rental
Grommet Kit 1/2 I.D.

Hobart 500495 Handler 125 MIG Gas Metal Arc Welder
30 pc. Precision Screwdriver Set
Craftsman 56 Piece Universal Tool Set
Imperial Triple Header Tube Bender
Woodward Fab Tube and Pipe Bender
DeWalt Compact Drill/Driver Kit
Brother Sewing Machine
204 Piece Master Drill Bit Set
Fabric Scissors
Rolling Cabinet Toolbox
Edsal Commercial Workbench [4]
National Public Seating Stool [5]

15

Capital Investment
Expense
$
15,000.00
$
10.99
$
739.98
$
13.98
$
79.99
$
45.00
$
299.99
$
99.00
$
464.97
$
39.99
$
8.49
$
279.99
$
339.04
$
127.45

Jet Drill Press
DeWalt Small Angle Grinder
Chain-break tool
Metric tap&die set
Hydraulic press
Silverline Hex Key Set

$
$
$
$
$
$

518.49
88.00
6.75
129.00
225.69
13.43

Cable Cutter

$

19.31

Desktop Computer
Hole Saw set
Jig Material and Hardware set

$
$
$

465.78
55.24
327.50

Table 10: In-House Labor Expenses

Welder
Seamstress
Assembler

In-House Labor Expense
Hours/
Position
week
40
40
40

Hourly Wage
$
$
$

18.00
11.00
19.50

Lastly, all of the previous tables were brought together to get a good understanding of
what the total costs would be for manufacturing 120 units of our competition vehicle annually.
Table 11: Total Expenses
Total Expenses
Total Parts and Material Expense
Total Outsourcing Expense
Total Capital investment
Total Labor Expense
Overhead Expense

$
$
$
$
$

2,659.83
4,398.05
216,000.00
15,000.00

Based on the numbers presented above we came up with a total vehicle cost (1-Year
Expense/120 units) of $1,983.82 (Table 12). This is, of course, the break-even cost of the
vehicle. In comparison to other vehicles currently on the market, our vehicle is running several
hundred dollars cheaper at break-even pricing. The Catrike 700 current MSRP’s for $2,750
whereas Terra Tikes’ Sportster MSRP’s at $2,299. When considering incurring a profit on our
vehicle we would most likely price our vehicle competitively with the Catrike 700 at about
$2,550.
Table 12: One and Three Year Total Expenses and Vehicle Production Cost
Total 1-Year Expense
Total 3-Year Expense
Vehicle Production Cost (1-Year Expense/120 Units)

16

$238,057.88
$714,173.63
$1,983.82

Other Analyses
Drivetrain
In order to achieve our top speed objective of 30mph a calculation of the gear ratio
required coupled with an average rider cadence was necessary. This analysis dictated what rear
hub specifications and chain-ring sizes were needed. Using Sheldon Browns Online Gear
Calculator [5] we were able to compile a set of tables for different rider cadences. The tables
used the gear ratio of the Shimano Alfine rear hub we selected to compare different front chainrings and rear cogs and output velocities at the specific chain-ring and cog combinations.
Assuming an average rider cadence of 80RPM the table told us that using a 46 tooth front chainring with a 16 tooth rear cog would propel us to 29.6MPH which is approximately 30RPM. Now
if the rider were to spin just a little bit faster they could easily reach over 30MPH. This
calculation affirmed our choice in the Shimano Alfine and defined which chain-ring and cog to
use in our configuration. The 80RPM configuration table is shown below, Figure 18.
80 RPM

16

0.53 (Low)
27.80%
36
7.6

1.42
46
9.6

12.50%

18

6.7

8.6

6.4

8.1

6

7.7

5.8

7.4

23.1

19
20
21

5.5

7

22

17.1

21.9

6.7

23

18

20.6

26.3

19

19.5

24.9

18.5

23.7

17.6

22.5

16.8

21.5

16.1

20.6

5.30%

16.3

20.8

20
5.00%

15.5

19.8

21
4.80%

14.8

18.9

4.50%

5.3

46
29.6

5.60%

4.80%

4.50%

23

18.1

5.00%

4.80%

22

18

16

1.62 (High)
27.80%
36
23.1

12.50%

5.30%

5.00%

21

46
26

5.60%

5.30%

20

27.80%

12.50%

5.60%

19

16

36
20.3

22
4.50%

14.1

18.1

23

Figure 18: Example partial section of top speed calculator table for rider cadence of 80RPM
Tie Rod
The tie rod is made of plated steel. The forces that will be exerted on the tie rod are
compression and tension which come from a rider not moving both steering arms in the same
direction. Equation (5) was used to find this force where is the yield stress of the bar, F is the
force being applied and A is the cross sectional area of the bar [11].
(5)
It was calculated that it would take a force of 1,457lb to make the tie rod yield in
compression or tension. The Humanics Ergonomics consulting firm did a case study on the
strengths of humans pulling and pushing on vertical cylinders. They found that the average male
can pull and push a vertical cylinder with 185lbf and 148lbf, respectively in a manner that is
much like how direct steering works [12]. Therefore the tie rod will have a factor of safety
above 7 for these types of loading.

17

Steel is stronger in compression than in tension but due to the tie rod being a long slender
rod buckling could be an issue. To calculate the force required to buckle the tie rod Equation (6)
was used where Pcr is the critical load, E is the modulus of elasticity for the material, I is the
moment of inertia, K is the end conditions for the rod and L is the effective length of the rod
[11].
(6)
The end conditions for the tie rod were assumed to be pin supported on both ends which gives a
value of 1 for K [11]. It was found that it would take a force of 322lb to make the tie rod buckle.
This allows for a factor of safety of 1.7 which is above our 1.5 safety factor objective for the
project.
Analyzing the bolt that is to attach the tie rod to the steering arm consisted of drawing a
free body diagram and finding the force required to cause the bolt to shear completely. Figure 19
shows how the free body diagram was set up. Force A and B are opposing forces that could
come from the rider trying to turn the wheels in opposite directions. Or they could be caused by
an impact on one of the tires which may twist the tire in an opposite direction of the other tire.

Force B

Bolt
Tie Rod

Steering Arm

Force A

Nut

Figure 19: Free body diagram of foces on bolt
The bolt will not be subjected to loads in tension or compression other than when it is hand
tightened when being assembled. Therefore we concluded that there was not a need to analyze it
for these conditions. However there will be shear loads applied to the bolt.
The M7x1 grade 5.8 coarse threaded steel bolt was selected because it was the largest
bolt we could use with the 5/16” through hole in the hemi joint that connects the tie rod to the
steering knuckle. Equations (7) and (8) were used to find the force required to yield the bolt in
shear [11].
(7)
(8)

18

Equation (7) uses the distortion energy theory in estimating the shear yield strength of ductile
material where Ssy is the shear yield strength and S y is the yield strength of the material [11].
Equation (8) gives the force needed to yield the bolt in shear where A is the cross sectional area
of the bolt. Values that were needed were found in the 5 th addition of Fundamentals of Machine
Component Design [11]. The force required to yield the bolts is 1972lbf.
Steering
The steering design is an important factor for stability while driving in a straight line and
while turning. When making a turn on a tadpole recumbent vehicle each of the front tires have
different turning radii which causes each tire to rotate at a different rate. This can be seen in
Figure 20 below.

Figure 20: Turning radius for each tire on a tadpole recumbent tricycle [13]
Due to the different radii and rotational speeds, tire scrubbing can occur. Tire scrubbing is when
the tire slides and rubs against the road which slows the vehicle down and waste energy. Peter
Eland has a website that has a section dedicated to developing steering for tadpole recumbent
tricycles [14]. To eliminate tire scrubbing Ackermann steering geometry is employed. This is
the geometry that keeps the front wheels at the correct angles through the turn. The important
geometry to achieve this are the distance from the center of the vehicle to center of the kingpin,
half the distance of LTrack in Figure 20, the steering arm length, the steering arm angle and the
wheel base, LWB in Figure 20. Using the spreadsheet available on Peter Eland’s website it was
found that dimensions of the Catrike 700 offered steering with a 5 % error from Ideal Ackerman
Steering [14]. Because we did decide to purchase the steering knuckles it does somewhat limit
us to using what the Catrike 700 has for lengths. However we believe that we would have
developed a similar size vehicle if we would have designed our own steering knuckles.

19

The next important aspects of steering are the kingpin, camber and caster angles. These
angles can be seen in Figure 21 below. Because we are purchasing our steering knuckles we will
be fabricating our steering to match the kingpin angle that the Catrike 700 has. The kingpin
angle is important for maintaining control of the wheels from steering effects caused by bumps
and holes in the road. The kingpin axis should meet up with the patch of tire that contacts the
road; this is called center point steering. The Catrike 700 has a kingpin angle of 24 degrees. The
camber angle is the angle measured from a perpendicular line from the road to the center line of
the tire. This angle helps to reduce the lateral load on the front wheels while making a turn.
Traditionally it is set to zero or a negative angle, meaning that the distance between the top of the
tires is less than the distance between the bottoms of the tires. From researching past vehicles
and trike building websites we have decided to have a camber angle of zero degrees. The caster
angle is the angle between vertical and the kingpin axis. This angle helps with stability while
turning and also self-centers the steering when coming out of a corner. Again from our research
and utilizing the Peter Elands website we decided to have a caster angle of around 10 degrees.

Figure 21: a) kingpin angle, b) camber angle and c) caster angle
Because the steering knuckles and axles are being purchased and will be used in a
manner that they were designed for we are confident that they will meet all design requirements
relating to feasibility. Table 13 below summarizes the angles for the steering.
Table 13: Direct Steering Angles
Direct Steering Angles:
Kingpin
Camber
Caster

Degrees
24
0
10

Storage Rear Rack
The rear rack of the vehicle was designed to safely support a maximum payload of two
panniers completely filled with water, weighing about 22.7 kg each. To ensure the 9.5mm
diameter 4130 alloy steel tubing selected for the rear rack would not fail under this load finite
element analysis using SolidWorks was performed and hand calculations validated the results.
The finite element analysis was set-up for only one side of the rear rack as it is symmetric about
a plane parallel to both sides. In the analysis a force of 45.6 kg was equally distributed along the
top rail of the rack. A force of 45.6kg was selected because dropping off a curb with the vehicle

20

can cause a force of double the pannier weight to be applied to the top rail of the rack when the
rear tire impacts the ground. The Von Mises Stress distribution from the finite element analysis
can be seen in Figure 20, which indicated a maximum stress of 115 MPa. Since 4130 alloy steel
has a yield stress of 460 MPa, the safety of factor for the rear rack predicted by finite element
analysis is 4.

Figure 22: Von Mises Stress Distribution of the Rear Rack
Due to the complex geometry of the rear rack the analysis calculations just examined the
ability of the vertical support member to resist loading. It was determined that the vertical
support member could support 334.7 kg before failing due to buckling. While the hand
calculations were highly idealized they confirmed that the finite element analysis results were
realistic. A safety factor of 4 is necessary for the rear rack as the loading conditions in the
analysis were highly idealized. The actual loading conditions will involve stress concentrations
and an uneven distribution of force along the top rail of the rack as the panniers will hang from
hooks.

Testing
RPS Testing
At this point in time our Roll Protection System (RPS) still needs testing. An explanation
of the results of our testing will be presented during the design competition in our updated report.
The following is the proposed test plan we have developed for the RPS when it is completed.
The goal of this test is to ensure that the RPS can withstand the 600lb top and 300lb side
loads respectively. The RPS will be attached to the frame and secured with using its two M6
class 5.8 bolts. The frame with the RPS will be secured below a loaded weight bar at an angle to
simulate the 12 degree angle the rules request. A special jig will be constructed and used to add
the weight safely to the top of the RPS. The 600lb weight will be left there unassisted for 30
seconds to be sure the RPS and frame do not fail. Measurements before and after the process will
be recorded to insure there is no permanent deformation. A similar process without the incline

21

will be conducted on the side of the RPS with 300lb load. We expect the RPS to withstand both
loads with minimum deflection and no permanent deformation.
Developmental Testing
Upon welding the original frame design the frame was taken out of the jig and with the
rear wheel attached and constraining the front head tubes the top of the frame was loaded
perpendicular to the length of the frame. The objective of this test was to see how the vehicle
would react to loads that created a moment on the main tube. After performing this test it was
decided that the main tube was not efficient by itself. Instead of having a separate seat and back
rest tubes as was originally designed, the tube for the seat and back rest would now be one
continuous part. This would help with any moments that may occur when pedaling the vehicle.
Figure 23 shows a picture taken before this test. Figure 24 below shows the frame design before
the change and after the design change.

Figure 23: Testing the main tube of the frame

Figure 24: Original frame (L) and redesigned frame (R)
Once this change was made all three tires where installed on to the frame and again the
frame was tested for stability and rigidity. The objective for the following test was to see how
22

the frame would react to pedaling forces. Pedaling was simulated by using straps secured to the
trike and a bolted down table to hold the vehicle from rolling backwards. The rider then sat on
the trike and pressed on the table with on leg at a time to see how the vehicle reacted to this
force. The rider would press with one leg then relax that leg and press with the opposite leg to
simulate pedaling. It was found that there was still too much rotation in the frame. The frame
also had large deflections at the seat ends near the steering arm when placing loads above the
rear triangle perpendicular to the length of the frame. To mitigate this rotation and deflection
tubing was added to connect the steering arm and seat tubes. Figure 25 shows the process of
adding this material.

Figure 25: Addition of material to make the frame more rigid
Upon the addition of this material and further testing it was decided that the deflection in the
frame would be acceptable. Figure 26 below shows testing of the frame after connecting the seat
tube and steering arm.

Figure 265: Testing the frame
Performance Testing
At this point in time the performance of the vehicle (top speed, turning radius, and
breaking) still needs to be tested. We will not test for stability because the wheel configuration of
our vehicle automatically satisfies the requirement and allows us to do so with little to no effort
or skill. An explanation of the results of our testing will be presented during the design

23

competition in our updated report. The objective, method, predicted results for testing the
different items listed are shown in Table 14 below.
Table 14: Testing objectives, methods, and results for the vehicles performance
Objective

Method

Predicted Results

Top speed

Verify theoretical top
speed and identify
rider with highest top
speed

Have each rider
propel their vehicle to
their fastest speed and
record the findings.

At least one rider will
be able to reach
30MPH and that
Blake Miner will be
the rider with the
fastest speed.

Turning radius

Verify minimum
turning radius and
verify turning radius
is within constraint

Have rider slowly
pedal the vehicle with
the wheels turned all
the way in one
direction and have a
person follow behind
the rear wheel with a
piece of chalk. The
resulting circle will be
measured for the
turning radius.

The turning radius
will be within our
constraint of 20ft.

Breaking

Verify that our
vehicle can stop
within the certain
requirements from a
required speed

Enter the braking trap
at a speed of
15.5MPH and apply
the brakes
immediately after
crossing the line until
the vehicle has come
to a complete stop.
Measure the distance
from the braking trap
start line to the front
wheels of the vehicle.

The braking distance
will be within our
constraint of 19.7ft.

Safety
Vehicle Layout
The decision for a recombinant three wheeled tadpole layout was based on the superior
stability at slow and high speeds it offered. The layout also allows for the center of gravity to lie
very low which helps prevent turnovers at high speed turns. A four inch ground clearance means
that we will still be able to climb standard speed bumps without issue. By making the vehicle
difficult to turn over we added a layer of safety rather than relying solely on the RPS to protect
the rider.

24

RPS
The Rollover/Side Protection System was designed to the ASME HPVC specification
and can support at minimum a 600lbf 12 degrees from vertical as well as a 300lbf on the side
with less than two inches of elastic deflection. The RPS bar forms a large loop above the head of
the rider which is robust enough to insure that, in the event of a rollover, the rider remains safely
in the envelope that’s created by the RPS and the wheels/pedals.
Seat belt
A three point racing safety harness has been purchased which, according to the
manufacturer is designed to meet or exceed specifications as set forth by SFI, FIA, USAC,
SCCA & (FMVSS) #209. As this report is being written, we are currently awaiting its arrival
but a quick update on is installation and performance will be delivered at the design presentation.
Visibility
Visibility of our HPV was a concern of ours because of how low recombinant trikes are
to the ground. The addition of the RPS extends the height of the vehicle an extra foot with it
resulting in a height of 46 inches, which is only about a foot shorter than the average car. The
height of the vehicle combined with the colorful panniers and fairing improved daytime
visibility. To address the safety of the rider at night, we have applied a glow in the dark paint to
the frame of the HPV to improve its visibility. Our energy storage system which is powered by
the moving wheels includes both break lights and a head light both of which will stay lit while
the trike idles at a stop light or other impediment. All of these elements combined with
traditional bike reflectors have been added for the safety of the rider and of bystanders.
Materials and Manufacturing
Materials selected for this vehicle were chosen based on the strength that chromoly has to
offer combined with the ease of finding materials and tool to repair it. Chromoly is a variation of
steel which means that it can be patched with other carbon steel using either MIG or TIG
welding. The only danger to the manufacturer that comes from using these kinds of materials is
the potential blindness and burns involved in welding it together without the proper skin and eye
protection. Chromoly also experiences ductile failures (if it does fail) which lowers the chances
of sharp edges that are common in brittle failures. The fabric fairing with its tent pole frame
present little danger to the rider in the event of a malfunction and may even be completely
removed if repair is inconvenient at the time.
Manufacturing safety was observed by the entire team throughout the development
stages. Manufacturing did not begin until a complete design and manufacturing process had been
developed. These plans included things like tool and cutting speed selection, budgeting time to
avoid human fatigue, and using the proper skin and eye protection when welding and grinding.
All manufacturing was done in a machine workshop that was complete with all precautionary
safety measures such as a fume hood, fire extinguishers, first aid kits and fire blanket just to
name a few.

25

Aesthetics
During the design of our vehicle we paid very close attention to details. The frame was
designed utilizing a few long bent tubes with fewer welds than using many short tubes. This
gives the vehicles frame a clean look by reducing the number of visible welds without sacrificing
structural rigidity. The few visible welds were grinded down to provide a clean finish. The
fairing was designed with swooping lines to give the vehicle a sense of sport. The panniers were
designed such that the re-used waste stream flowed nicely with the rest of the vehicle. The rack
with which the panniers connect to was kept simply and sleek as to not be very visible from the
side when the panniers are on the vehicle. This makes it seem like the panniers are holding
themselves up. Outside of the frame construction there are few other manufactured parts on the
vehicle. This keeps clutter to a minimum and leaves just the components on the bike. Design for
cable routing placed the shifter cable underneath the seat and the energy storage cables in the
seat rail. This keeps loose and ugly cables from hanging all over the vehicle and adds to the sleek
look. All of The vehicles controls were designed to mount directly to the handlebars. This keeps
the controls and cables centralized and not all over the vehicle.

Conclusion
Comparison
Once vehicle testing commences, this table will be updated with the analysis
Table 15: List of Objectives and Constrains
Objective/Constraint

Method of Measurement

Target

Analysis

Vehicle Weight
Top Speed
Turn Radius
Ground Clearance
Entry/Exit Vehicle
Braking
*RPS Top Load
*RPS Top Elastic Def.
*RPS Side Load
*RPS Side Elastic Def.

Weight [lbs]
Speed [mph]
Distance [ft]
Height [in]
Time [sec]
Distance [ft] and Speed [mph]
Weight [lbs]
Distance [in]
Weight [lbs]
Distance [in]

<65
>30
<20
>3
<7.5
19.7 at 15.5
600
2
300
1.5

53.79
44.4

Testing

3.125
N/A
N/A
1200
0.0705
600
0.112

Evaluation
Below is a bulleted list describing how the final vehicle will be evaluated with respect to the
objectives and constraints from Table 15.






Vehicle weight (<65lbs) –Weigh vehicle on scale and record reading.
Top speed (>30mph) – Ride the vehicle equipped with a bicycle speedometer. Record the highest
achieved speed.
Turn radius (<20ft) –Ride the vehicle in a circle and measure the turning radius of the vehicle center.
Ground clearance (>3in) – Physically measure distance between lowest point on vehicle and ground.
Entry/exit vehicle (<7.5s) – Physically measure a rider, standing outside of the vehicle, get into the
vehicle, completely close the fairing, and put their feet on the pedals.

26







Braking (19.7ft at 15.5mph) –Record vehicle stopping distance from a speed of 15.5mph.
Repeat and average the values. This test will be performed on both wet and dry surfaces.
RPS Top Load (600lbs) –Rest a bar loaded with 600lbs on top of the RPS and verify that it
holds.
RPS Top Elastic Deformation (2in) - Rest a bar loaded with 600lbs on top of the RPS and
measure deflection.
RPS Side Load (300lbs) – Rest a bar loaded with 300lbs on the side of the RPS and verify that it
holds.
RPS Side Elastic Deformation (1.5in) - Rest a bar loaded with 300lbs on the side of the RPS
and measure its deflection.

Recommendations
 Do not build anything prematurely when you are not completely sure of the dimensions or
any other physical characteristics unless it is completely necessary.
 An improvement can be made in the roll protection system. Something that will make it
slimmer and less of a distraction.
 The vehicles torsional stiffness can be improved by modifying the geometry.
 The vehicles boom and adjustability configuration could be redesigned and/or improved.
 The fairing can be improved to be more modular.
 The seat can be improved in such a way that it does not slide down over time and use.
Conclusion
Although our vehicle has not been fully tested to date we believe that our design
objectives will be met. Over the course of the past eight months we have been through rigorous
design and analysis. Our design is robust and our analysis proves that. We see no reason why our
testing should deviate far from our analysis. Structurally, with respect to the frame and roll
protection systems, we used high factors of safety, high enough to prevent high impact and static
loads. Many of our other components such as our wheels and tires, steering assembly, bottom
bracket assembly, chain, brakes, and internally shifting hub were purchased and have been well
developed by companies for years. These components should have no problem during testing
because they are being used exactly as they were designed. We are confident that our vehicle
will prove to be strong, durable, reliable, versatile, fast, and agile such that we will be a top
contender in the 2013 American Society of Mechanical Engineers Human Powered Vehicle
Competition.

27

References
[1] (n.d.). Retrieved March 08, 2013, from
http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA7075T6
[2] (n.d.). Retrieved March 09, 2013, from
http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA7075T6
[3] (n.d.). Retrieved March 09, 2013, from
http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA7075T6
[4] Apadopoulos, D. G. (2004). Bicycle Science. The MIT Press.
[5] Brown, S. (2012, December 10). Sheldon Brown's Gear Calculator. Retrieved November 10,
2012, from Sheldon Brown's Bicycle Technical Info: http://sheldonbrown.com/gears/
[6] Hase Bikes. (n.d.). Retrieved March 08, 2013, from Klimax 2K: http://hasebikes.com/83-1Klimax-2-K.html
[7] Indeed. (n.d.). Retrieved March 08, 2013, from http://www.indeed.com/
[8]American Society of Mechanical Engineers. (2011, Nov). The Tradition of ASME HPVC
Develops Socially Minded Engineers (ME Today, Nov 2011) [Online]. Available:
http://www.asme.org/kb/newsletters/me-today/me-today---november-2011-issue/thetradition-of-asme-hpvc-develops-socially-minde
[9]American Society of Mechanical Engineers. (2012, August 31). Human Powered Vehicle
Challenge [Online]. Available: http://www.asme.org/events/competitions/humanpowered-vehicle-challenge-%28hpvc%29
[10]E. N. Wilmsen. (2009, May 7). Colorado State University Engineering Students Win
National Honors in Human-Powered Vehicle, SAE Formula Competitions [Online].
[11]R. C. Juvinall and K. M. Marshek, Fundamentals of Machine Component Design, 5th ed.
Danvers, 2012.
[12]University of Nottingham. Ergonomics Data for Strength. [Online]. Available:
http://www.humanics-es.com/strength.pdf
[13]D. Hipwood, E. Jarvis, M. Porter, B. Schlueter, C. Sednek, M. Shirley, “2009 ASME Human
Powered Vehicle West Coast Challenge Design Report” Colorado State University, Fort
Collins, CO, 2009.
[14]

Peter Eland. Steering [Online]. Available: http://www.eland.org.uk/steering.html

28

Appendix I (Innovation Report)
Objective
The objective of the dual purpose fairing innovation is to increase the vehicles versatility
while not sacrificing aerodynamics. The objective of the recycled cat litter panniers is to create a
practical, durable, and inexpensive pannier for transporting personal items.
Need
The need addressed by the dual purpose fairing, outside of the fairings general purpose of
breaking wind and protecting the user from the environment, deals with shelter and packing
weight. If the rider is going on a multi-day trip they will need shelter overnight. The dual
purpose fairing gives the user a light shelter and eliminates them from having to haul a tent. This
reduces the users overall packing weight and allows for more space for essential necessities. The
cat litter panniers primary purpose is to address the need of having a storage device on the
vehicle. The panniers provide waterproof and rugged storage and each pannier has a volume of
20 liters. Off the vehicle the panniers can be carried around and used as portable storage
containers for personal items or water. Another important need the panniers fulfill is reducing the
environmental impact of creating a new project. Cat litter bins are a current waste product in
society. By repurposing old cat litter bins into panniers the bins are kept out of landfills or the
recycling stream and reused.
Description
The dual purpose fairing is composed of a tent pole skeleton. The tent poles have been
strategically bent to give the fairing its aerodynamic profile. The tent pole skeleton is attached to
the vehicle by a chromoly steel mast. Both the fairing and the chromoly mast can be easily
removed from the vehicle. The fairing is clasped onto the end of the fairing mast via tool less
wing nuts and to eye bolts in the rear via carabineers. This makes rider ingress/egress quick and
installation/removal of the fairing easy and tool free. The “skin” of the fairing is made from
waterproof/breathable Ripstop Nylon and clear Vinyl. Velcr’d to the inside the cockpit, rolled up
neatly and compactly, is a piece of Ripstop Nylon that can be unraveled. When removed from
the vehicle, the entire shelter is fastened to the ground via guy-lines and stakes. On the market
today exists fabric fairings from the German manufacturer Hase [6]. Hase equips their newest
model, the Klimax, with a removable fabric fairing but the fairing does not double as a shelter.
The idea of a removable fairing/shelter is a brand new idea to our knowledge. Figure 1 shows a
solid model of a cat litter pannier for the left side of the vehicle. The pannier utilizes the Ortlieb
QL1 mounting system [2]. The QL1 system features two hooks that can slide back and forth on a
top rail. This allows for the panniers fore and aft position on the vehicle to be adjusted. The top
rail will be bolted onto the cat litter bin in-between the top ribs with spacers to prevent the hooks
from hitting the ribs on the cat litter bins. On the back of the panniers there will be reflective
stickers to add to the nighttime visibility of the vehicle. There will also be a webbing
handle/strap to carry the pannier and hold its lid down. This handle will attach to the top rail of
the Ortlieb hooks and buckle into a strap attached to the webbing anchor on the front of the
pannier. Another feature of the handle/strap is that is can be used to hold something like a
sleeping pad on the top of the pannier.

29

Figure 1: Solid Model of a Cat Litter Pannier
Literature Review
As mentioned above, a German manufacture Hase makes recumbent tricycles equipped
with fabric fairings. Using the internet, a Google search was employed to find inspiration and
technical details in regards to using fabric for fairing material. Hase uses poles similar to tent
poles for their collapsibility and a Ripstop Nylon material but, as mentioned earlier, our fairing
differs in its geometry, frame construction, and functionality (as a shelter). This innovation is
new enough and differentiable enough that it is patentable. The idea of making panniers out of
old cat litter bins has been circling around the cycling community and internet for several years
in the form of do it yourself projects. Extensive online research was unable to find any
commercially available cat litter panniers or any patents referencing the idea. The Ortlieb QL1
hooks used in the cat litter pannier design were patented in 1993 under the patent number
EP0643655 B1 in Europe and US5673833 in the United States, but this patent has since expired
and the hooks can be used on any pannier product. Our design for the cat litter panniers differs
from all other designs in that it uses the Ortlieb QL1 hooks and has a custom webbing handle.
The combination of different features in the design of the cat litter panniers and the lack of any
patents pertaining to its idea means that the innovation is new enough to patent.
Testing and Evaluation
Testing and evaluation of the fairing includes two phases: drag coefficient and rider
ingress/egress. With respect to rider ingress/egress the rider must be able to do so within 7.5
seconds. For rider ingress, a person with a stop watch will record the time it takes a rider,
standing outside of the vehicle, to get into the vehicle, completely close the fairing, and put their
feet on the pedals. Rider egress will be tested and evaluated just the opposite of the ingress.
Testing and evaluation of the fairing will be less rigorous. The only testing and evaluation at this
point is if the fairing successfully stays on the vehicle during operation. We will rely on the
rough estimation for the drag coefficient and the fact that having a fairing is better than not
having one. Unless we can measure the CD in a wind tunnel we have no other way of evaluating
our fairings effectiveness. Testing and evaluation of the pannier system includes simply loading
the panniers with a parcel of volume less than 1560in3 and weighing less than or equal to 12 lbs.
Evaluation of this test is as follows: does the parcel fit into the pannier and does the pannier hold
the weight without failing? If these two questions are answered as “yes” then the pannier system
has been design successfully.

30

Market Analysis
The marketability is high given the rise of outdoor industry related activities and more
people taking extended trips in non-motorized vehicles. Such would be the markets that this
fairing would be marketed to: outdoor enthusiasts, adventurers, and people with recumbent
tricycles. The cost of the fairing itself will cost considerably less than a rigid fairing based off of
raw material costs, labor costs, and manufacturing costs. Also, too, premade tent poles can be
arranged with manufactures to come pre-bent thus reducing the overall cost when bought in bulk.
The benefits to the user are high. As it was mentioned earlier, the user has a complete
aerodynamic device that cuts down on wind resistance, increases their efficiency, shields them
from the environmental elements, reduces the amount of overall gear necessary to pack, and
allows for the user to pack more of the essentials in the space that a conventional tent would have
taken up. With the trend to buy products that have lower environmental impacts and more people
using bicycles for transportation cat litter panniers have a high market potential. The cat litter
panniers could be manufactured for about $20 a pannier and sold for $40 a pannier, which is less
than half the retail price of other waterproof panniers on the market costing about $100 dollars a
pannier. The target market for cat litter panniers would be environmentally conscious consumers
who use their bicycle for transportation. These consumers would quickly accept the new cat litter
pannier product as it offers all of the advantages of a traditional waterproof pannier at less than
half the price and is much ‘greener’.
Conclusions and Recommendations
This style of fairing is definitely a new idea and we believe will increase the appeal and
attractiveness to touring in a recumbent tricycle. The fairing itself is highly capable of
performing cross functionally and it is effective in both arenas. The tent pole skeleton geometry
should be continued to be experimented with in future development as well as connecting the
tent pole ends directly into the Chromoly support system. This would reduce the level of
complexity and would further increase the sophistication of the system. The cat litter panniers
are an innovative way to reuse a current waste product and turn it into a fully functional storage
device for human powered vehicles. The panniers are quick and easy to remove from or attach to
the vehicle, keep contents dry in all weather conditions, and are very durable. Currently there is
no similar product on the market and consumers would be quick to accept the idea due to its
functionality and low cost. Prior to any commercial sales of this product the design needs to be
refined through rigorous testing of the pannier’s performance under extreme conditions.
References
[6]
Hase Bikes. (n.d.). Retrieved March 08, 2013, from Klimax 2K: http://hasebikes.com/831-Klimax-2-K.html
[2]
Hartmut Ortlieb, 1993, “Device for holding bags on bicycles, motorbicycles or the like,”
Europe, United States, EP0643655A1, US5673833.
[11] R. C. Juvinall and K. M. Marshek, Fundamentals of Machine Component Design, 5th ed.
Danvers, 2012.
[12] University of Nottingham. Ergonomics Data for Strength. [Online]. Available:
http://www.humanics-es.com/strength.pdf
[13] D. Hipwood, E. Jarvis, M. Porter, B. Schlueter, C. Sednek, M. Shirley, “2009 ASME
Human Powered Vehicle West Coast Challenge Design Report” Colorado State
University, Fort Collins, CO, 2009.

31

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